Once again, let's take one thing at a time: "I mean that she works. she has an employer that issued her a w-2. which probably is not important to the question I asked."

Okay, is this what you are stating: "She has a Real Job working for someone else, and the pastry operation is a side-gig she started doing."

See how perspective helps?

"but there is no employees of the LLC"

A single-member LLC that has no employees, not even this person, means it is Not acting as a corporation. Have you checked with the IRS, because they will have a record of the election? For instance, if you file using 1120 or 1120S, there should have been Payroll for her, and if there never was election to be treated as a Corporation, the IRS will kick it back as an error.

So far, you seem to have a Schedule C operation, but it's Your name, not ours, when you file this as the professional preparer. Have you done as much due diligence as possible, or not?